Wiping them out is hard to do when they take whole cities hostage and are embedded among the innocent, and have many captive “brides.” We would have to stoop to their level. However, I do think we should blow up the trucks they are using to take oil to Turkey. Drop message to truck drivers they have 1 minute run like heck, then bomb the trucks.
Drop leaflets
Destroy two or three blocks of the city
Everyone else runs and they don’t care about ISIS. They run.
Word gets around. The leaflets hit the ground and everybody runs without having to destroy anymore.
Combine that with Special OPs and allowing the civilians a little revenge on the ISIS pigs and word will get around.